1. Field of the Invention
The present invention relates to an endoprosthesis stent delivery system and a method of using an endoprosthesis/stent delivery system, and particularly, to a system and method for deploying an endoprosthesis/stent within a hollow organ.
2. Discussion of the Related Art
In general, stent/endoprosthesis devices are placed within hollow organs, such as veins, arteries, esophagus, colon, and pancreatic tracts, to re-open or reinforce flow pathways through the hollow organs. One type of stent/endoprosthesis device is formed of a cylindrical wire mesh placed over an expandable balloon. Once the stent is delivered to the desired location, the balloon is inflated and expanded, thereby expanding the stent against interior sidewalls of the hollow organ. Then, the balloon is deflated and withdrawn from the hollow organ, thereby leaving the expanded stent within the hollow organ.
Another type of stent 1, as shown in FIG. 1, is formed of a self-expanding cylindrical wire mesh, but is compressed along an axial catheter 2 by a sheath 3 concentrically disposed about the axial catheter 2 before placement into a hollow organ 13 using a guide wire 4. The sheath assembly, which includes the axial catheter 2 and the sheath 3 with the compressed stent 1, is inserted into the hollow organ 13, and the compressed stent 1 is positioned at a targeted location P within the hollow the organ 13. Once the assembly is inserted into the hollow organ 13, and the axial catheter 2 and the compressed stent 1 are positioned at a targeted location P within the hollow organ 13, the sheath 3 is withdrawn along an axial length of the compressed stent 1 to allow for radial expansion of the stent 1 against the interior sidewall 15 of the hollow organ 13 due to the spring forces Fx and Fy of the compressed stent 1 along the x-axis and y-axis. However, precise placement of the stent 1 at targeted location P is difficult and the actual final positioning of the stem 1 is often unpredictable due to the spring forces Fx and Fy associated with the expansion of the stent 1. As a result, final location or position of the inner end of the stent 1 may be undesirably positioned a distance d from the target location P.